Samsung 6s won't work in China, even with Chinese SIM Card

[AC Question]

I've got a Samsung Galaxy galaxy s6 edge plus purchased in America, I used it in Hong Kong with a local SIM card and it was fine. A month later I'm in China and I got a China Telecom and Internet didn't work, though wifi connection worked. I also cant get calls, I get texts 12 hours after they are sent, and when I call a Chinese number my phone thinks I'm calling someone in America. I swapped to China Unicom but exact same issues. Local Samsung people can't figure it out, American setup on the phone is different than same phone in China. Any fixes to this problem?

 

[the tall guy]

Hi, did you ever manage to get this resolved?